Canterbury Park trainer Mac Robertson punished after horse tests positive for banned substance

Mac Robertson, the leading trainer in Canterbury Park history, was provisionally suspended Monday for a failed postrace drug test and could face a two-year ban.

The suspension was announced by the Horseracing Integrity and Welfare Unit (HIWU), a new federal agency that took over drug testing at all U.S. tracks in May. The ruling said a horse in Robertson's barn, the 5-year-old gelding Johnny Up, tested positive June 4 for altrenogest. That drug is allowed in female horses to regulate the reproductive cycle but is a banned substance in male horses.

Under HIWU rules, a positive test for a banned substance triggers an automatic provisional suspension. Horses in Robertson's barn must be transferred to other trainers. The penalty is a two-year suspension and a fine of up to $25,000, though sanctions could be as little as a reprimand if "no significant fault or negligence'' were found.

Robertson currently is in second place in Canterbury Park's annual trainer standings with 13 victories from 63 starts. He is the track's all-time leader in most training categories, including wins (1,038) and purse earnings ($22.9 million).

Robertson did not respond to a text message seeking comment.

Johnny Up won the fifth race on Canterbury's June 4 card, for Minnesota-breds with a claiming price of $7,500. Robertson runs one of the largest stables at Canterbury, with about 70 horses.

Dr. Lynn Hovda, chief veterinarian for the Minnesota Racing Commission, said altrenogest is used commonly at racetracks. According to manufacturer Merck Animal Health, it controls the reproductive cycle of fillies and mares to reduce "undesirable mood and behavioral changes,'' allowing them "to compete at their best.'' The drug is a liquid administered via oral syringe, either into the horse's mouth or on its feed.

Under Canterbury's previous drug-testing rules, altrenogest was barred from use in male horses. But according to presiding racing steward Randy Blaseg, the penalty would have been about a $1,000 fine, plus loss of the purse money. The punishment recommended by the Association of Racing Commissioners International is a $1,000 fine and loss of purse.

"I'm more than a little surprised at the [HIWU] recommended penalty,'' Blaseg said. "It seems a little much.''

According to the thoroughbredrulings.com database, Robertson had 11 positive tests between 2008 and 2010, all of them for anti-inflammatory medications that are permitted but must be out of a horse's system on race day. His stable has had two positive tests in the past 13 years.

In 2015, one of his horses tested positive at Canterbury for a trace amount of methamphetamine; Robertson said he did not know how the drug got into the horse and fired two employees who tested positive for meth. He received a 90-day suspension and $2,000 fine. In 2020, Robertson was fined $1,000 in Delaware when a horse tested positive for an anti-inflammatory medication over the allowable limit.

Monday's suspension was the first doping violation reported at Canterbury since HIWU assumed control of drug testing and enforcement May 22. The agency is affiliated with the Horseracing Integrity and Safety Authority, launched by the federal government last July to create uniform safety and drug-testing standards for horse racing.

In the past, testing at Canterbury was overseen by the Minnesota Racing Commission's veterinary staff, following rules established by the racing commission. Canterbury's stewards, who also are racing commission employees, administered sanctions for violations. That was the case throughout the country, with each racing jurisdiction setting its own regulations and protocols.

HIWU now handles all those duties under uniform national rules. The new regulations include more severe sanctions than those typically handed down by state racing commissions.

According to the HIWU database, five trainers and one veterinarian have been provisionally suspended for banned medication infractions. Five others have pending cases related to controlled substances, which are allowed but regulated.